The present invention relates generally to the field of airborne matter collection devices.
Air sampling devices are generally used to determine the quantity and types of matter present in a gas (e.g., air or other gaseous atmospheres). For example, in a factory where materials are used that may be detrimental to human health, it may be desirable to determine the amount and types of matter present in the atmosphere so that factory workers are not exposed to unsafe or undesirable levels of airborne materials. In other examples, air sampling devices may be used in a variety of environments, including, but not limited to, office buildings, houses, hospitals, clean rooms, or outdoors.
Sampling devices conventionally include a collection device (e.g., a particle impaction device, microscope slide, petri dish, or other device) for collecting and retaining matter included in the gas being sampled. In use, the sampling device draws a gas (e.g., air) toward the collection device. Matter (e.g., viable and/or non-viable matter) included in the gas impacts a substance or material (e.g., a collection medium) provided on or in the collection device, where the matter is retained until analysis can be performed. One known type of collection device is a cassette or cartridge type sampling device, such as the Air-O-Cell product manufactured by Zefon International, Inc. of Ocala, Fla.
One difficulty associated with the use of some known collection devices is that the collection devices may become contaminated with continued use. For example, after sampling is complete, the collection medium (e.g., agar medium) is removed from the collection device and the collection device is cleaned. Remnants of past samples and media may remain after cleaning, which may affect results of subsequent sampling.
Another difficulty with conventional collection devices is that moisture levels may be uncontrolled near the collection medium. It is desirable, especially in the case of living organisms, that the sampled matter be maintained at an appropriate moisture level such that the sample neither dehydrates nor is over-hydrated to the point that the organisms continue to grow. In either case, such situations may lead to inaccurate information concerning the sampled matter.
One potential solution is the use of a dessicant to remove moisture in the vicinity of the collection medium. However, dessicants tend to simply dehydrate the collected matter instead of maintaining humidity at a desired level, which may not be suitable for living organisms.
It would be desirable to provide a relatively simple and inexpensive system for controlling the moisture level of sampled gas-borne matter to prevent dehydration and growth (i.e., to maintain the moisture level at an equilibrium level that is suitable for maintaining the samples without promoting growth). It would also be desirable to provide a system for storing and/or shipping sampled matter that maintains the moisture level of the sampled material.